Imessage

I just got the iPhone 14 pro and had it set up and everything, but when I text other people with iPhones, it shows I have an android. I also can’t be added to iMessage group chats because it says I don’t have iMessage. When I text people, it shows green as well, even if they have an iphone. I tried turning imessage on and off in setting but it says activation was unseccessful.